Black screen after attempted GPU install. Please help!

AuroraHD

Honorable
Feb 18, 2014
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10,790
So I recently changed my PSU and got an Asus gtx 760 DIRECT CU II gpu. My computer was prebuilt with AMD A8 3850 processor. I installed the card, plugged in the power cords and a green light appeared on the card. I turned on the computer, it started with a beep, and the display was on, but black with a flashing under square at the top. It beeped a total of 3 times. Now, I don't know what the reason is, but I can guess it's either the motherboard or the bios. Do I have to uninstall old drivers first? I still have AMD drivers on my computer. And if I were to uninstall old drivers and the card still won't run, will I be able to log back in windows? Also, do I maybe have to set the bios to detect the pcie or something? Or is it my motherboard?

Current build:
APU: AMD A8 3850
GPU: Asus GTX 760 DC2 OC
Mobo: MSI A75MA G55
OS: Windows 7
PSU: Cooler Master i700 80+

Tons of ideas are very welcome!!